A campaign to promote train safety featuring animated characters involved in extremely Dumb Ways to Die has been named the best TV advertising campaign in the world, pipping Channel 4's Meet the Superhumans ad for the London Paralympics.

Dumb Ways to Die, a clever public service message from Metro Trains in Melbourne, has swept all before it becoming the most successful ad campaign in the history of the Cannes International Festival of Creativity.

The TV and online ad, which features characters killed in bizarre ways such as poking a bear with a stick and swimming with piranhas to push the idea that deaths due to silly activity on or around trains are the most pointless, has become an internet hit notching up more than 50m views on YouTube.

The campaign, by agency McCann Melbourne, has taken five grand prix awards, the most that a campaign has ever notched up at the awards. It has won the film, radio, PR, direct and integrated categories.

It is the second year running that the top film award has gone to a campaign with a social message — US fast food chain Chipotle won last year with a similarly-styled animation-with-music ad about sustainable farming and production.

Channel 4's Meet the Superhumans campaign to change the image of Paralympic athletes ahead of the London 2012 Games, which featured the Public Enemy track Harder Than You Think, picked up a Gold Lion.

Sir John Hegarty, co-founder of ad agency BBH and president of the 23-strong jury, said of the campaign: "When you've got some really outstanding work it is tragic in some ways it can't get a bigger award, but there can only be one grand prix".

Jury member Carlo Cavallone, executive creative director at agency 72andsunny, expanded on the judging process: "[Meet the Superhumans] is an amazing campaign, one of the golds that went through [the judging process] immediately," he said. "Everyone felt it had the highest level of craft. It puts an issue that was really important before London 2012 to raise awareness of the Paralympics [and] they were hyper successful … Dumb Ways to Die was a tough contender. Amazing music piece, amazing editing."

The Australian ad industry is on something of a creative hot streak with Tourism Queensland's "best job in the world campaign", a cleverly exploited stunt to find a caretaker for an Australian paradise island, scooping three grand prix awards in 2009.

The jury took the highly unusual step of awarding two grand prix awards in the film category this year. The other was given to a long-form piece of online video content from Intel and Toshiba. The campaign was shot as a six-part miniseries about a man who wakes up every day as a different person.

The only other time that there has been a joint winner in the film category in the 60-year history of the awards was in 2008. That year Cadbury's drumming gorilla TV ad had to share the top award with a viral campaign for Xbox's Halo 3 game.

The jury was somewhat disdainful about a growing trend of agencies submitting very long pieces of video content used for online campaigns.

Hegarty said that just because the internet is free of the restrictions of the time limits governing TV ads does not mean that agencies should make long online video pieces.

"There is a great danger in that word 'long-form'," he said. "One of the great things about films is the ability to edit."

Jury member Ant Keogh gave a warning to agencies to think hard before submitting long-form TV series-like content for judging in future. "Is it as good as an HBO show? [Because] that is what you are up against," he said.

• This article was amended on 26 June 2013. An earlier version of this article said the Dumb Ways to Die advert had more than 500m views on YouTube. This has been corrected to say 50m.